Finishes are applied to fibers, including aramid fibers, for numerous reasons, such as avoiding fiber damage during processing, lessening friction with processing equipment so the equipment is not worn out quickly and the fiber is easily processed, modifying the feel ("hand") of the fiber, etc. For ballistic uses, aramid fibers with two conflicting properties are desired--low coefficient of friction with the process equipment, usually metal and/or ceramic, and a high fiber-fiber coefficient of friction, particularly when both are measured at higher speeds. The latter is believed to give fabric with improved ballistic properties. This sometimes necessitates the use of a first finish for processing, removal of the first finish, and then application of a second finish to provide high fiber-fiber friction. It is a goal of this invention to provide an aramid finish that gives fibers with relatively low fiber-metal (or ceramic) coefficients of friction, and relatively high fiber-fiber coefficients of friction.
U.S. Pat. Nos. 3,198,754 and 3,300,274 report that certain fluorinated aziridines and their polymers are useful for treating textiles. Aramids are not mentioned, and frictional properties are not discussed.
U.S. Pat. No. 3,575,890 reports that certain fluorinated polyoxazolines can be used to treat fabrics to impart oil and water repellency. Aramids and frictional properties are not mentioned.
U.S. Pat. Nos. 3,147,065 and 3,147,066 report that certain fluorinated compounds containing quaternary ammonium groups can be used to treat textiles to impart oil and water repellency. Aramids and frictional properties are not mentioned.